Joint lock

A joint lock is a grappling technique involving manipulation of an opponent's joints in such a way that the joints reach their maximal degree of motion and hyperextension.

In judō these are referred to as kansetsu-waza (関節技, "joint locking technique"^[1]) and in Chinese martial arts as chin na, which literally means "catching and locking". In Korea these are referred to as gwan-jerl-gi (관절기, joint skill) or gwan-jerl-kerk-gi (관절꺾기, joint breaking).

Joint locks typically involve isolating a particular joint, levering it in an attempt to force the joint to move past its normal range of motion. Joint locks generate varying degrees of pain in the joints and, if applied forcefully and/or suddenly, may cause injury, such as muscle, tendon and ligament damage and even dislocation or bone fracture.

In judo, the combining of standing locks with throws is forbidden due to the risk of physical harm to the falling opponent, while Brazilian jiu-jitsu, jujutsu, taijutsu, aikido, sambo, and hapkido allow their use.

Joint locks can be divided into five general types according to which section of the body they affect:

• Armlocks
• Leglocks
• Small joint manipulation
• Spinal locks
• Wristlocks

These general types can be further divided into subtypes according to which specific joint(s) they affect, or the type of motion they involve.